Answer:
0.31 mol
Explanation:
Many scientists have contributed to the atomic theory. In 1803 John Dalton gave new insight to this theory. Which desciption of an atom fits our most
current understanding?
Fyry nyyden atom is the same as every hydrogen atom
If 550 grams of KClO3 breaks down and produces 175 grams of KCl, how many grams of O2 are produced?
Answer:
215.51 g of O2.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2KClO3 —> 2KCl + 3O2
Next, we shall determine the mass of KClO3 that decomposed and the mass of O2 produced from the balanced equation. This is illustrated below:
Molar mass of KClO3 = 39 + 35.5 + (16×3)
= 39 + 35.5 + 48
= 122.5 g/mol
Mass of KClO3 from the balanced equation = 2 × 122.5 = 245 g
Molar mass of O2 = 16 × 2 = 32 g/mol
Mass of O2 from the balanced equation = 3 × 32 = 96 g
From the balanced equation above,
245 g of KClO3 decomposed to produce 96 g of O2.
Finally, we shall determine the mass of O2 produced by the decomposition of 550 g of KClO3. This can be obtained as follow:
From the balanced equation above,
245 g of KClO3 decomposed to produce 96 g of O2.
Therefore, 550 g of KClO3 will decompose to produce =
(550 × 96)/245 = 215.51 g of O2.
Therefore, 215.51 g of O2 were obtained from the reaction.
A beam of electrons (m = 9.11 × 10-31 kg/electron) has an average speed of 1.9 × 108 m/s. What is the wavelength of electrons having this average speed, in picometers?
Answer:
12 pm
Explanation:
Step 1: Given data
Mass of an electron (m): 9.11 × 10⁻³¹ kgAverage speed of an electron (v): 1.9 × 10⁸ m/sSpeed of light (c): 3.00 × 10⁸ m/sPlanck's constant (h): 6.63 × 10⁻³⁴ J.sWavelength of an electron (λ): ?Step 2: Calculate the kinetic energy (E) of an electron
We will use the following expression.
E = 1/2 × m × v²
E = 1/2 × 9.11 × 10⁻³¹ kg × (1.9 × 10⁸ m/s)²
E = 1.6 × 10⁻¹⁴ J
Step 3: Calculate the wavelength of an electron
We will use the following expression.
E = h × c / λ
λ = h × c / E
λ = 6.63 × 10⁻³⁴ J.s × 3.00 × 10⁸ m/s / 1.6 × 10⁻¹⁴ J
λ = 1.2 × 10⁻¹¹ m
Step 4: Convert "λ" to picometers
We will use the relationship 1 m = 10¹² pm.
1.2 × 10⁻¹¹ m × (10¹² pm/1 m) = 12 pm
The wavelength of the beam of electrons is 3.8 pm.
Using the De Broglie relation;
λ = h/mv
λ = wavelength
h = Plank's constant
m = mass of the object
v = speed of the object
Now;
λ = ?
h = 6.6 × 10^-34 Js
m = 9.11 × 10^-31 kg
v = 1.9 × 10^8 m/s
So;
λ = 6.6 × 10^-34 Js/ 9.11 × 10^-31 kg × 1.9 × 10^8 m/s
λ = 6.6 × 10^-34 /1.73 × 10^-22
λ = 3.8 × 10^- 12 m or 3.8 pm
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Why do silver and copper have similar properties? (science CER)
Answer:Copper is a chemical element with the atomic number 29, and the chemical symbol Cu. Silver is also found on the periodic chart of elements, and has a chemical symbol of Ag and an atomic number of 47.
Explanation:
Both silver and copper are transition metals of d-block in periodic table they are in the same group and thus shows similar chemical and physical properties.
What is group in periodic table?In periodic table, elements are classified into groups and periods. The horizontal rows are called periods and the vertical columns are called groups.
There are 18 groups and 7 periods in periodic table. Elements of the same group have same number of valence electrons and similar chemical and physical properties.
Silver, copper and gold are in 11th group of periodic table. Thus they have 9 valence electrons and exhibit similarity in properties. All these metals are good conductors and are used in electrical and optoelectronic devices.
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what is the hydronium ion concentration in a solution formed by combining 750mL of 0.10M NaOH with 250mL of 0.30 M HCl
Answer:
[tex][H^+]=1x10^{-7}M[/tex]
Explanation:
Hello.
In this case, since the reaction between sodium hydroxide and hydrochloric acid has a 1:1 mole ratio between them:
[tex]NaOH+HCl\rightarrow NaCl+H_2O[/tex]
In order to compute the hydronium H⁺ concentration in the mixed volumes of the given solutions we first compute the moles of each reactant:
[tex]n_{NaOH}=0.750L*0.10mol/L=0.075mol\\\\n_{HCl}=0.250L*0.30mol/L=0.075mol[/tex]
As seen, since those amounts are the same, we infer all the acid and base are consumed so the pH is 7 because a neutral salt is produced, and the corresponding H⁺ concentration is:
[tex][H^+]=10^{-pH}=10^{-7}=1x10^{-7}M[/tex]
Best regards!
A liquid has rhe following properties : one-phase,colorless,boils it varying temperature. Which of the following BEST describes this liquid
A.Solution
B.substance
C.suspension
D. Coarse mixture
Answer:
Solution
Explanation:
In science, the solution is a homogeneous mixture of two or more pure substances in proportional concentrations that can be continually varied up to what has been called the solubilization limit. The word solution is usually applicable to the fluid subatomic particle, but gaseous formulations are conceivable.
Please help I need to turn this in already
Answer:
The acceleration will be .5 and the force will be 37.5
Have a nice day! :)
Answer:
Hello. The answer is 37.5N.
Explanation:
If you look carfully ، every time that you add one weight the force changes 2.5N so you can do this:
[tex](2.5 \times 5) + 25 = 37.5[/tex]
Joebert had a rectangular cup and filled it with water. He measured the water's mass and volume. Then he got a density of 1.25g/ml. If the accepted density of water is 1 g/ml, what was the percent error of his measurement?
someone can help me please?
Answer:
Percent error = 25%
Explanation:
Given data:
Measured density of water = 1.25 g/mL
Accepted density value of water = 1 g/mL
Percent error = ?
Solution:
Formula:
Percent error = (measured value - accepted value / accepted value) × 100
Now we will put the values in formula:
Percent error = (1.25 g/mL - 1 g/mL /1 g/mL )× 100
Percent error = (0.25 g/mL /1 g/mL )× 100
Percent error = 0.25 × 100
Percent error = 25%
Which statements about mixture is FALSE?
A. The ingredients ofvthe mixture keep their physical properties
B. Mixture components can be separated
C. All mixtures are food or drink only
D. A mixture contains more than one ingredients
Fluorine is the first element in Group 17 of the periodic table. Bromine is the third element in the same group. Which statement is true of both
elements?
A. Both of their ions will have the same positive charge.
B. The charge on the ion formed by fluorine will be less than the charge on the bromine ion.
C. The charge on the ion formed by fluorine will be greater than the charge on the ion formed by bromine.
D. Both of their ions will have the same negative charge.
Answer:D. Both of their ions will have the same negative charge
Explanation:
help pls
Which process of sedimentary rock formation occurs last?
cementation
compaction
deposition
erosion
Answer:
Compaction.
Explanation:
All the others are before this.
Why does sodium chloride form a crystal lattice
Answer:
Ions of opposite charge strongly attract each other; those of like charges repel. As a result ions in an ionic compound are arranged in a particular manner.
Explanation:
Google is smart
Please help fill in the blanks: The torso, which houses the apparatus consists of upper and lower cavities that are partitioned by the________.The upper cavity is called the _____ (or colloquially the chest) and is almost totally filled with the heart and lungs; the lower the cavity, the abdomen or belly, contains much of the ____ and other organs and glands.
Answer:
The torso, which houses the apparatus consists of upper and lower cavities that are partitioned by the diaphragm. The upper cavity is called the thoracic cavity (or colloquially the chest) and is almost totally filled with the heart and lungs; the lower the cavity, the abdomen or belly, contains much of the digestive tract and other organs and glands.
Explanation:
The torso, which houses the apparatus consists of upper and lower cavities that are partitioned by the diaphragm. The upper cavity is called the thoracic cavity (or colloquially the chest) and is almost totally filled with the heart and lungs. The thoracic cavity also contains the esophagus, the channel through which food is passed from the throat to the stomach.
The lower the cavity, the abdomen or belly, contains much of the digestive tract and other organs and glands such as the liver, the spleen, the kidneys, as well as the adrenal glands.
What are the similarities between the adrenal hormone cortisone and the synthetic corticoid prednisone?
a. Both have a steroid nucleus
b. Both have 3 ketone groups
c. Both have 2 methyl
d. Both have 2 hydroxy group
e. Both have the same number of double bonds.
Answer:
Options a,b, c and d are correct
Explanation:
From the diagram attached in the picture below, They both have steroid nucleus since they have functional groups (such as the methyl and the ketone groups) that are spatially attached. It can also be deduced that both structures have three (3) ketone groups (CO/C=O), two (2) methyl groups (CH₃) and two (2) hydroxyl groups (OH). Hence, options a, b,c and d are correct.
However, cortisone has one (1) double bond while prednisone has two (2) double bonds.
How many atoms of Carbon are found on the PRODUCTS side?
Physical and chemical changes occur all around you every day. Read the story below and use the movable
highlighter pieces to highlight the physical changes in PURPLE and the chemical changes in ORANGE.
The physical changes are:
"blend up a banana smoothie instead"."cut a piece of bread in half"."I cracked two eggs and whipped them with a fork"."water had evaporated"."glass breaking"."Steam was rolling out"."broke off a piece"."the chocolate melted".The chemical changes are:
"the milk had soured"."was covered in brown spots"."it was completely tarnished"."plants were dying"."toast must be burning"."rusted bicycle".Changes of matterMatter can undergo 2 kinds of changes:
Physical changes: matter changes form but not its identity.Chemical changes: matter changes its identity due to a chemical reaction.Let's consider the following text.
When my alarm went off at 70'clock, I hit snooze" a few times then finally got out of bed with excitement for my morning bowl of cereal. I poured the cereal and milk into my bowl. But before I even drank it, I could tell from the smell that the milk had soured! So, I decided to blend up a banana smoothie instead. I took some ice out of the freezer and grabbed the only banana that we had in the kitchen, which was covered in brown spots. My grumbling stomach needed to be satisfied before school so I didn't really care.
Just as I was sitting down to drink my smoothie my little brother came bounding into the kitchen and asked, Would you make some eggs and toast for me for breakfast?
"Ugh, sure," I said. I cut a piece of bread in half and put it in the toaster, then I cracked two eggs and whipped them with a fork. I reached for one of my mother's copper cooking pans in the cabinet and saw that it was completely tarnished! I didn't want to be blamed for this, so I ran to tell my mother right away. As I ran out of the kitchen slipped on that banana peel and it smeared all over the floor. As I lay on the floor with the wind knocked from me, I noticed that our family's plants were dying and that some water had evaporated from our fish tank. I made a mental note to take care of these things after school.
Just as I regained my breath and stood up, I heard glass breaking upstairs and my mother shrieking. I ran up the stairs, breathing heavily now. Steam was rolling out from the open bathroom door. When the steam cleared, saw why my mother had been screaming. Before me was my older sister standing in the bathroom with purple hair. I inferred from the scene that my mother had dropped a glass when she first saw her look what your sister did to her hair my mother yelled furiously I decided that I needed to get out of the house immediately, this morning was a crazy one!
A distinct smell was waiting up the stairway and I realized that my brother's toast must be burning! When reached the kitchen, my brother was happily spreading butter on his very browned toast. "I like my toast really crispy!" he said.
"Good I can't handle any more chaos this morning! I exclaimed. I grabbed my backpack headed out into the foggy morning air, and hopped on my slightly rusted bicycle to ride to school. A few minutes into my ride, my stomach grumbled and I realized that I never got a chance to drink my banana smoothie. Luckily, I had stashed a chocolate bar in my backpack yesterday. "Yes! I thought as I stopped pedaling, grabbed the chocolate and broke off a piece. As the chocolate melted in my mouth, I knew that my day was bound to get better!
The physical changes are:
"blend up a banana smoothie instead"."cut a piece of bread in half"."I cracked two eggs and whipped them with a fork"."water had evaporated"."glass breaking"."Steam was rolling out"."broke off a piece"."the chocolate melted".The chemical changes are:
"the milk had soured"."was covered in brown spots"."it was completely tarnished"."plants were dying"."toast must be burning"."rusted bicycle".Learn more about physical and chemical changes here: https://brainly.com/question/17384175
Green light has a wavelength of 510 nm. What is the wavelength in meters?
Which set of procedures would be best to follow when separating a mixture of sand, salt, and water?
Answer:
Pour the mixture through a filter to separate the sand, then evaporate the liquid to separate the salt.
Explanation:
There are various methods used to separate single substances from a mixture. The method adopted depends upon the type of mixture and the ingredients used in it. According to the given question, the mixture comprises of sand, salt and water. Here, the first process will be the process of filtration. Through filtration, the salt-water solution and sand can be separated. Salt-water solution can be separated by the process of evaporation in which sat and water will be separated individually.
A. In a separatory funnel containing ethyl acetate and 10% aqueous sodium bicarbonate (NaHCO3), which layer would contain the brominated aromatic compound?
Answer:
ethyl acetate layer
Explanation:
This question tests your knowledge of the principle of solvent extraction.
In solvent extraction, there is always an organic layer and an aqueous layer. The ethyl acetate is the organic layer while the sodium bicarbonate is the aqueous layer.
A brominated aromatic compound will be extracted into the organic layer (ethyl acetate layer).
how many atoms are in 20.34 grams of aluminum (Al)
A) 6.02 x 10^23 atoms
B) 4.54 x 10^23 atoms
C) 4.54 atoms
D) 548.8 grams
Notice that the value 12.01 grams of natural carbon is the same as the atomic mass value (12.01 amu). It also tells us that 20.34 grams of aluminum contains exactly 6.022 x 1023 atoms of aluminum.
✅
So, the answer is A) 6.02 x 10^23 atoms
IamSugarBee
Answer:
Option A: 6.03 * 10^23 atoms
When 2.16g of H2 reacts with excess O2 by the following equation, 258 kJ of heat are released. What is the change of enthalpy associated with the reaction of 1.00 mol of hydrogen gas? 2H2+O2⟶2H2O
Answer:
-241 kJ/mol
Explanation:
Let's consider the reaction of hydrogen with excess oxygen to form water.
2 H₂ + O₂ ⟶ 2 H₂O
When 2.16g of hydrogen reacts with excess oxygen, 258 kJ of heat are released, that is, Q = -258 kJ. Considering that the molar mass of hydrogen is 2.02 g/mol, the change of enthalpy associated with the reaction of 1.00 mol of hydrogen gas is:
ΔH° = -258 kJ/2.16 g × (2.02 g/1.00 mol) = -241 kJ/mol
The mercury level in a capillary tube placed in a dish of mercury is actually below the surface of the mercury in the dish. Please choose the answer that best explains the phenomenon.a. Mercury flows freely and is incapable of clinging to the walls of the capillary tube. b. Mercury has an incredibly high density for a liquid, making it too heavy to climb the capillary tube, c. The cohesive forces of mercury are much stronger than its adhesive forces. The adhesive forces may be repulsive, causing the mercury level in the tube to be lower than the mercury in the dish. d. Mercury is a polar molecule. It creates incredibly high cohesive forces, which prevent the mercury from climbing the capillary tube.
Answer:
The cohesive forces of mercury are much stronger than its adhesive forces.
Explanation:
Cohesive forces are forces that exist between the particles that compose a substance while adhesive forces refer to forces that exist between the particles of a substance and those of another substance.
The cohesive forces in mercury far outweigh the adhesive forces between the mercury drops and glass. Hence when mercury is put into a capillary tube, its meniscus is convex because cohesive forces tend to draw the liquid mercury into a drop.
Hence, the surface tension in mercury makes the mercury in the capillary tube to fall below the height of the mercury in the dish.
Aspirin is a weak organic acid whose molecular formula is HC9H7O4. An aqueous solution of aspirin is prepared by dissolving 3.60 g/L. The pH of this solution is found to be 2.6. Calculate Ka for aspirin. (atomic mass: C
Answer:
Ka = 3.50x10⁻⁴
Explanation:
First, we need to convert the unit of 3.60 g/L to mol/L:
[tex] C_{C_{9}H_{8}O_{4}} = 3.60 \frac{g}{L}*\frac{1 mol}{180.16 g} = 0.0200 mol/L [/tex]
The reaction dissociation of aspirin in water is:
C₉H₈O₄ + H₂O ⇄ C₉H₇O₄⁻ + H₃O⁺
0.02 - x x x
The constant of the above reaction is:
[tex] Ka = \frac{[C_{9}H_{7}O_{4}^{-}][H_{3}O^{+}]}{[C_{9}H_{8}O_{4}]} [/tex]
[tex] Ka = \frac{x^{2}}{0.02 - x} [/tex]
To find Ka we need to find the value of x. We know that pH = 2.6 so:
[tex] pH = -log[H_{3}O^{+}] [/tex]
[tex] 2.6 = -log(x) [/tex]
[tex] x = 2.51 \cdot 10^{-3} M = [H_{3}O^{+}] = [C_{9}H_{7}O_{4}^{-}] [/tex]
Now, the concentration of C₉H₈O₄ is:
[tex] C_{C_{9}H_{8}O_{4}} = 0.02 - 2.51 \cdot 10^{-3} = 0.018 M [/tex]
Finally, Ka is:
[tex] Ka = \frac{[C_{9}H_{7}O_{4}^{-}][H_{3}O^{+}]}{[C_{9}H_{8}O_{4}]} = \frac{(2.51 \cdot 10^{-3})^{2}}{0.018} = 3.50 \cdot 10^{-4} [/tex]
Therefore, the Ka of aspirin is 3.50x10⁻⁴.
I hope it helps you!
A block of lead weighs 11.3 grams. How many atoms of lead are in this sample?
• Use 6.022 x 1023 mol
for Avogadro's number.
Answer:
To get the number of atoms in this sample, we first need the number of moles of lead in 11.3 grams
Number of moles of Lead:
Molar mass of lead = 207 grams / mol
Number of moles = given mass / molar mass
Number of moles = 11.3 / 207
Number of moles = 0.05 moles
Number of atoms of lead in 11.3 gram sample:
Number of atoms = Number of moles * avogadro's number
Number of atoms = 0.05 * 6.022 * 10²³
Number of atoms = 5 * 10⁻² * 10²³ * 6.022
Number of atoms = 30.11 * 10²¹
11.3 g block of lead contains 3.29×10²² atoms
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.022×10²³ atoms. Thus,
1 mole of lead = 6.022×10²³ atoms
Recall:
1 mole of lead = 207 g
Thus,
207 g of lead = 6.022×10²³ atomsWith the above information in mind, we can obtain the number of atoms in 11.3 g block of lead as illustrated below:
207 g of lead = 6.022×10²³ atoms
Therefore,
11.3 g of lead = (11.3 × 6.022×10²³) / 207
11.3 g of lead = 3.29×10²² atomsThus, 11.3 g block of lead contains 3.29×10²² atoms
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Suppose that Biuret reagent turns purple when it is added to an unknown substance. What can you conclude about the substance?
Answer:
the unknown substance is a protein
Explanation:
The biuret test is one of the tests for proteins. It can be used to detect peptide linkages. The biuret test is carried out in an alkaline solution. A coordination complex is formed leading to the appearance of a violet color.
Summarily, the biuret method is a colorimetric technique used to test for proteins and peptides. It involves the formation of a purple (violet) complex of Copper salts in alkaline solution.
Hence when the biuret reagent is added to an unknown substance and it turns purple, the unknown substance is a protein
What does wadding do?
Answer:
Wadding is a disc of material used in guns to seal gas behind a projectile or to separate powder from shot. ... Wadding for muzzleloaders is typically a small piece of cloth, or paper wrapping from the cartridge.
Explanation:
What does not represent a compound
Answer:
Every combination of atoms is a molecule. A compound is a molecule made of atoms from different elements. All compounds are molecules, but not all molecules are compounds. Hydrogen gas (H2) is a molecule, but not a compound because it is made of only one element.Explanation:
When you finish exercising, you are hot, tired, and sweating. After a bottle of juice, you feel a lot better. Which organ systems are working together in this scenario?
Answer:
Nervous and Excretory
Explanation:
The nervous system makes you thirsty. The integumentary system makes you sweat. the integumentary system is very similar to the Excretory system.
Nervous and Excretory systems are working together in this scenario.
The nervous system makes you thirsty. The integumentary system makes you sweat. the integumentary system is very similar to the Excretory system.
The blood flow increases, your brain is exposed to more oxygen and nutrients. Exercise also induces the release of beneficial proteins in the brain. Sweating cools the body when it becomes warm. When the body temperature rises, such as when exercising on a hot day, the dermal blood vessels dilate.The excretory system works with the endocrine system to help maintain homeostasis.Learn more:
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What two types of elements make up an Ionic bond ?
Answer:
Metals and Non-metals
Explanation:
I Need Help Please ?
Answer:
Not sure dude goodluck
Explanation: